# 0
# 所谓工厂函数,就是类的构造函数

# 1
# 当实例对象进行加法操作时候,调用__add__()

# 2
# 变量名和方法名不能覆盖

# 4
# 就是py风格呗

# 动手吧

# 0
class Nstr(str):
    def __sub__(self, other):
        return self.replace(other,"")

nums = [1,2,4,6]
name = str(nums)
print(name)

a = Nstr('i am a gundam!!!!')
b = Nstr('!')
print(a - b)
